The present invention relates to a device for attaching an optical unit to a holding apparatus as well as a method for attaching an optical unit.
When using optical units, one uses holding apparatuses to arrange an optical unit in the desired position. For the quick exchange of optical units on stands, quick-change adapters are known, which allow for a non-screwed connection of the optical unit to the stand. The known quick-change adapters comprise a clamping plate that is attached to the optical unit and an attachment plate that is attached to the stand, wherein the clamping plate can be attached to the attachment plate via a clamping mechanism. EP 0 982 613 B1 discloses a quick-change adapter with a clamping plate and an attachment plate, which has a swallowtail-shaped guide with a stationary first profile groove and a second profile groove that can be adjusted via a clamping mechanism. For attaching purposes, the clamping plate is inserted into the profile grooves and the second profile groove is pulled against the attachment plate by the clamping mechanism so that the clamping plate is fixed to the guide of the attachment plate.
This type of quick-change adapters has proven to be reliable and easy to handle; however, the known quick-change adapters are inflexible in regard to various clamping plates, since these must be matched precisely to the swallowtail-shaped guide of the attachment plate. In addition, the clamping plates must be adapted to the respective optical unit.
In contrast, the object of the present invention consists of developing quick-change adapters for optical units, which are suited for all optical units with a standardized thread receiver.
In doing so, the ease of handling and the high reliability of the known quick-change adapters are to be retained.
This task is achieved for the device mentioned earlier for attaching an optical unit according to the invention, and for the method mentioned earlier for attaching an optical unit. Advantageous developments are stated in the dependent claims.
The device according to the invention for attaching an optical unit, which comprises a cylindrical receiving opening, on a holding apparatus, has:                a housing with a plurality of housing parts,        an actuating device with an adjustable actuating element,        an expansion sleeve with multiple expansion segments, which can be adjusted in a plane perpendicular to a longitudinal axis of the expansion sleeve between a closed state and an expanded state, and        a first adjusting device, which transforms a movement of the actuating device into a radial movement of the expansion segments in the plane perpendicular to the longitudinal axis of the expansion sleeve,wherein the expansion segments, in the closed state of the expansion sleeve, can be inserted into the receiving openings of the optical unit and, in an expanded state of the expansion sleeve, form a force- or form-fitting connection with the receiving opening of the optical unit.        
The device according to the invention enables one to attach an optical unit on a holding apparatus using the adjustable actuating element. To do so, the optical unit with the receiving opening is fit on the expansion sleeve, which is in a closed state. Then, the expansion segments are expanded by means of the actuating device and the first adjusting device in the plane perpendicular to the longitudinal axis of the expansion sleeve. In the expanded state, the expansion segments form a force- or form-fitting connection with the receiving opening of the optical unit.
The term “optical units” includes within the scope of the present invention all devices that utilize an optical or electro-optical component. Examples of optical units are laser receivers, laser distance measuring devices, line laser devices, rotating laser device, photo cameras, and video cameras. What all optical units have in common is that they have in the housing a cylindrical receiving opening, by means of which the optical unit can be attached to a holding apparatus. The base of the receiving opening can be circular, square, polygonal, or designed with another cross-sectional shape.
For a receiving opening with a circular base, there may also be provided on the outer surface an interior thread that can form a threaded connection with a complementarily designed exterior thread of a holding apparatus.
Among holding apparatuses, one differentiates between stands, which are positioned in a freestanding manner on a substrate, mobile holding apparatuses, and stationary holding apparatuses. Mobile holding apparatuses are handheld by users and can be moved in the room, such as measuring sticks, levelling rods, and poles. Stationary holding apparatuses use elements in the measuring environment, which have a different function and are used by the user; examples for stationary holding apparatuses are wall adapters, rail adapters, pipe adapters, and magnetic adapters. The device according to the invention is suited for all holding apparatuses, which secure an optical unit via a threaded connection. The holding apparatuses have a screw, which is screwed into a matching thread receiver on the optical unit.
Preferably, the first adjustment apparatus is designed as a core pin that can be adjusted along an axial direction, wherein the core pin is surrounded by expansion segments and the axial direction runs parallel to the longitudinal axis of the expansion sleeve. The core pin is surrounded by the expansion segments of the expansion sleeve, which are adjustable in a radial plane perpendicular to the longitudinal axis of the core pin. The translational movement of the core pin in the axial direction is transformed into a radial movement of the expansion segments perpendicular to the longitudinal axis of the core pin. By the radial movement of the expansion segments, the expansion sleeve can be adjusted between the closed state and the expanded state.
All directions parallel to the longitudinal axis of the expansion sleeve are defined as an axial direction, and all planes that are arranged perpendicular to the longitudinal axis of the expansion sleeve are defined as a radial plane. The radial direction is a direction that runs in a radial plane and cuts through the longitudinal axis of the expansion sleeve.
In a particularly preferred manner, the core pin has a cone section with cone-shaped exterior surfaces and the expansion segments have complementarily designed, cone-shaped interior surfaces, wherein the interior surfaces of the expansion segments slide along the exterior surfaces of the core pin during the movement of the core pin in an axial direction. The translational movement of the core pin in an axial direction is transformed by means of the cone section into the radial movement of the expansion segments. Due to the design of the cone-shaped exterior surfaces on the core pin and the cone-shaped interior surfaces on the expansion segments, the movement of the core pin in the axial direction can be converted into the radial movement of the expansion segments.
The cone-shaped exterior surfaces of the core pin can be integrated in a common surface, for example a cone or truncated cone surface, or the cone-shaped exterior surfaces are composed of multiple cone-shaped partial surfaces. A cone-shaped surface is a rotation surface that is formed by a curve rotating about an axis. For converting the translational movement of the core pin in the axial direction to a radial movement of the expansion segments, it is important that the exterior surfaces and interior surfaces assigned to each other are designed in a complementary manner.
In a particularly preferred manner, the core pin has, besides the cone section, a step section and a cylindrical section, wherein the cylindrical section is surrounded by a first spring element, which is clamped between the adjustable step section and one of the stationary housing parts of the housing. When the core pin is moved in an axial direction toward the expansion sleeve, the first spring element is compressed. The first spring element is preferably designed as a return spring and ensures that the expansion segments are moved back to their starting position when the actuating element is moved backward.
In a particularly preferred manner, the expansion segments have on each of their interior surfaces a first guide element and the core pin has two guide elements designed to complement the exterior surfaces, wherein the expansion segments are guided during the movement of the core pin in the axial direction by means of the first and second guide elements. The guide elements, which are designed as swallowtail guides for example, ensure that the expansion segments are moved by the core pin from the expanded stated to the closed state when opening the connection.
The first guide elements of the expansion segments are designed in a particularly preferred manner as a projection and the second guide elements of the core pin are designed in a particularly preferred manner as complementarily designed grooves. This design of the guide elements allows a compact configuration of the expansion sleeve.
In a preferred embodiment, the expansion elements each have on the exterior side a connecting section and a ring collar section, wherein the connecting sections in the expanded state from a force- or form-fitting connection with the receiving opening of the optical unit and the ring collar sections in the expanded state form in the axial direction a form-fitting connection with one of the stationary housing parts of the housing. The connecting sections are inserted into the receiving opening of the optical unit and can form a force- or form-fitting connection with the receiving opening. The type of connection, namely a force fit or a form fit, thereby depends on the exterior geometry of the connecting sections. The ring collar sections serve to secure the optical unit against a translational movement in the axial direction. By means of the radial movement of the expansion segments, the ring collar sections can grasp from behind one of the stationary housing parts and secure the optical unit on the adapter. The ring collar sections of the expansion segments can be designed in a one-piece manner or consist of a plurality of parts.
In a particularly preferred manner, the connecting sections of the expansion segments have an exterior thread, wherein the exterior thread forms a form-fitting connection with a receiving opening, designed as a thread receiver, of the optical unit in an expanded state. In doing so, the properties of the exterior thread are adapted in a particularly preferred manner to the interior thread of the thread receiver.
The expansion segments are in contact, on the interior side, with the core pin via cone-shaped interior surfaces; the interior surfaces of the expansion segments slide along the exterior surfaces of the core pin. The expansion segments are inserted in the receiving opening of the optical unit and can form on the exterior side a force- or form-fitting connection with the receiving opening. The structural design of the expansion segments on the interior sides is independent of the structural design of the expansion segments on the exterior sides. Thus, preferred designs of the expansion segments on the interior side, such as cone-shaped interior surface and guide element, can be combined in any desired manner with preferred designs of the expansion segments on the exterior side, such as a connecting section and ring collar section.
A development of the device provides for a clamping ring and a second adjusting device, wherein the second adjusting device transforms a movement of the actuating device into a movement of the clamping ring in the axial direction. By means of the clamping ring, which can be adjusted by means of the second adjusting device, a tilting of the optical unit relative to the longitudinal axes can be avoided or at least remedied. The structural design of the second adjusting device is independent of the first adjusting device with the core pin and expansion sleeve. For that reason, preferred designs of the first adjusting device can be combined in any desired way with preferred designs of the second adjusting device.
In a particularly preferred manner, the second adjusting device comprises a pressure plate and a plurality of cylindrical pins, wherein the cylindrical pins are surrounded by second spring elements, which are clamped between the adjustable pressure plate and one of the stationary housing parts of the housing. When the pressure plate is moved in an axial direction toward the expansion sleeve, the second spring elements are compressed. The second spring elements are preferably designed as return springs and ensure that the pressure plate is moved back to its starting position when the actuating element is moved back.
In a particularly preferred manner, the actuating element can be adjusted between a first position, a second position, and a third position, wherein the first adjusting device converts the movement of the actuating element between the first and second position into the radial movement of the expansion segments in the plane perpendicular to the longitudinal axis of the expansion sleeve, and the second adjusting device converts the movement of the actuating element between the second and third position into the movement of the clamping ring.
In a particular preferred manner, the actuating device comprises a control disk having a first control region and a second control region, wherein the first control region moves the core pin in an axial direction and the second control region moves the pressure plate in an axial direction. The adjustment region of the actuating device is divided into two angular regions: in the first angular region, the core pin is moved by the first control region in an axial direction, and in the second angular region, the pressure plate is moved by the second control region in an axial direction. The control curves of the first and second control regions are thereby preferably matched to each other in such a manner that in the first angular region, only the core pin is moved in an axial direction, and in the second angular region, only the pressure plate is moved in an axial direction.
The present invention also relates to a holding apparatus with a device according to the invention for attaching an optical unit. In a first preferred variant, the device according to the invention for attaching an optical unit can be connected in a detachable manner to the holding apparatus so that the device can be retrofitted for conventional holding apparatuses. In a second preferred variant, the device according to the invention for attaching an optical unit is connected to the holding apparatus in a non-detachable manner. The second variant is particularly suited for new holding apparatuses, which may be designed more compactly. All optical units with a standardized threaded connection can be attached to the holding apparatus.
The device according to the invention has the advantage that no modifications are necessary on the threaded connection of the optical units. Since the threaded connection of the optical units is not modified, all optical units can be attached to conventional holding apparatuses as well as to holding apparatuses that use the present invention.
According to the invention, the method for attaching an optical unit, which comprises a cylindrical receiving opening, on a quick-assembly adapter is characterized in that:                the optical unit with the receiving opening is fitted on an expansion sleeve with a plurality of adjustable expansion segments, wherein the expansion sleeve is in a closed state, and        the expansion segments are converted from a closed state into an expanded state by means of an actuating device and a first adjusting device in a plane perpendicular to a longitudinal axis of the expansion, wherein the expansion segments in an expanded state form a force- or form-fitting connection with the receiving opening of the optical unit.        
The method, according to the invention, has the advantage that an optical unit can attach on a stand by means of an adjustable actuating element. The optical unit can be easily and quickly attached to the stand or detached from the stand by the user. The laborious opening and closing of the threaded connection
In a preferred development of the method according to the invention, after placing the expansion sleeve into the expanded state, a clamping ring is moved by means of the actuating device and a second adjusting device in an axial direction parallel to the longitudinal axis of the expansion sleeve toward the optical unit. Using the clamping ring, which can be adjusted by means of the second adjusting device, a tilting of the optical device in relation to the longitudinal axes can be prevented or at least remedied.
Embodiments of the invention will be described below using the drawing. It is not intended to represent the embodiments to scale necessarily; rather the drawing, where useful for explanatory purposes, is executed in a schematic or slightly distorted form. In regard to supplements to teachings directly evident from the drawing, one shall refer to the relevant prior art. One shall thereby take into account that diverse modifications and changes pertaining to the form and detail of an embodiment can be undertaken, without deviating from the general idea of the invention. The invention features disclosed in the description, the drawings, as well as the claims may be relevant both individually per se as well as in any combination for the development of the invention. In addition, falling within the scope of the invention are all combinations of at least two of the features disclosed in the description, drawings, and/or claims. The general idea of the invention is not limited to the exact form or detail of the preferred embodiment shown and described below or limited to a subject matter that would be restricted in comparison to the subject matter claimed in the claims. For provided measurement ranges, values lying within the mentioned limits shall be disclosed as limits and may be used and claimed arbitrarily. For simplicity's sake, the same reference signs are used below for identical or similar parts, or parts with identical or similar functions.